body {
    min-width: 8.5333rem;
    max-width: 20rem;
    margin: 0 auto;

}

// 当页面大于750px 文字大小不变
@media screen and(min-width:750px) {
    html {
        font-size: 1rem;
    }
}

a {
    text-decoration: none;
    color: #707070;
}

.header {
    height: 2.24rem;
    border-bottom: 1px solid#ccc;
    text-align: center;
    line-height: 2.24rem;
    font-size: 1.6rem;

}

.nav {
    display: flex;
    // 强制换行
    flex-wrap: wrap;

    a {
        margin-top: .2667rem;
        display: flex;
        flex: 33.33333%;
        // 水平居中对齐
        flex-direction: column;
        align-items: center;

        img {
            height: 3.7067rem;
            width: 3.7067rem;
        }

        span {
            font-size: .6667rem;
        }
    }

}